Can fuel even thrust itself at the speed of light pushing a 0 mass load?
This doesn’t help. The fuel tanks don’t just have to be on the trajectory of the vessel; they have to be moving at the same velocity, hence requiring the same amount of energy per unit mass. The only advantage to this would be if there were some scaling problem in the propulsion system such that it would make sense to break up the mass into separate vessels, but one might as well launch them all at the same time.
No, nothing with mass can achieve c, period. This is a basic limitiation of the natural laws of the universe as far as we have been able to describe, and we have described this behavior to many orders of magnitude of accuracy many different ways.
Stranger
Two decent size capules and long wires/cables/trusses.
And yes its not trivial. But not nothing else in space is either. And maybe it is ridiculously hard. But AFAICT they haven’t even tried that. (well, I think they might have sorta did a very short very low G thing with two docked Gemini capsules spinning about a bit).
This is a proposal that is conceptually feasible (e.g. there is nothing physically impossible about it or would require some radical advancement of fundamental technology) but actually making the systems to do this would be beyond the current experience and capability. It would require a means to spin up the system, some kind of stabilization to prevent unwanted precession and nutation, a counterrotating hub or tether at the midpoint at which to dock and attach systems such as solar panels which are non-rotating, and of course, would have to be strong enough to withstand the acceleration forces and large enough to be habitable for the period which one would want to study the inhabitants (months or years). A space station that met these requirements would probably cost an order of magnitude more than the ISS and would have to be far more carefully designed (as opposed to the rather slapdash construction of the ISS). So, it is workable, but well beyond the budget that NASA could sustain.
Stranger
Has science ever detected the slightest hint that a demensionaly larger universe traveling faster than the speed of light might exist, or has anything odd ever been detected that could indicate this possibility?
Yes, otherwise, your space-wrangling solution amounts to accelerating them up to speed when you catch them (which is the same as decelerating the vessel you’re flying)
The other problem is that unless you spend a lot of fuel accelerating the fuel pods, or launch them a very long time (thousands of years) before you set off, they won’t be very far ahead of you anyway.
True, but at least we can put bounds on the problem. 1/3 G is almost certainly not worse than 0 G. And we have techniques for ameliorating problems associated with 0 G. We don’t yet have any techniques for dealing with long-duration hypergravity.
I’m sure that for $100M, one could build a giant centrifuge with a small apartment on the end. Cheaper than a single manned rocket flight. There’s just no practical application for a very, very long time.
Well, the other advantage is that the main (manned) vessel can accelerate at 1 G, while the fuel vessels could go higher than that.
Suppose we had a large local accelerator that could launch pods to a very high velocity (with no need of rockets), but only with high accelerations. Just as a for instance, suppose we have a 1,000,000 km accelerator that will bring pods up to 1% of the SoL. By necessity, it will subject the load to ~4500 m/s^2, or 460 Gees. Obviously, no human could survive this.
So what you do is send out these fuel pods in advance, timing them so that the passenger ship (accelerating at a gentle 1 G via rocket) will catch up to the pods at the right moment. Done right, there’s no relative velocity between them when the paths intersect.
Oops–I thought about it more and it doesn’t quite work. The pods will have to speed up to meet with the ship, since if the ship is closing in it must have a higher velocity. But I think they won’t burn quite as much fuel as they otherwise would have (and again, they can accelerate more than a human can handle). If the accelerator is “free”, it should still be a net win.
And the opposite applies as well. We can imagine fuel/supply pods that take WAY longer to get to speed X at position Y (in space) than the generational ship does. They are launched way in advance. But that is okay because its just some basic parts and computers waiting thousands of years longer than necessary, not a bunch of humans. And this also has the advantage of being able to test all this stuff for that long in the real world before the humans actually set out.
Successfully intercepting the pods would be an interesting challenge - the further you send them, the greater the magnification of even the smallest error in their heading (and your own) will become. The pods would need some kind of course-correction apparatus, because changing your own course to catch them, when they have all diverged in different ways, would be expensive, maybe impossible).
Yeah… though I think that’s not too difficult a problem, relatively speaking.
BTW, I think the accelerator will always save (approximately) half the delta-V. The two craft must obviously intercept at the same distance and velocity. For whatever the intercept distance is, the passenger craft will have maintained an average velocity half that of the final velocity. The fuel pod has maintained a constant velocity for most of its journey, and so that velocity must equal the average of the passenger craft if the distances are to be equal. Thus, the fuel pod must double its velocity as its last sprint to match speeds with the passenger craft.
Given the Tsiolkovsky rocket equation, that’s actually a pretty big benefit.
Actually, I’m not sure that interpolation is valid here, since I’d expect a near-discontinuity just above zero. If you’re working in, say, 1/6 g, you could give a person a lead suit with five times the mass of a human distributed around it, and let them walk around as normal, and one would intuitively expect that that would be similar, for many purposes, to the person walking around on Earth. You can in principle do this for any nonzero acceleration, though at some point the suits would get too bulky, and you’d also have to worry about F = ma. This doesn’t really work at all in zero g, though.
Yay, my idea isn’t useless!
You don’t physically have to catch the pods, btw.
They can dump their hydrogen, and you catch it with magnetic fields, ramscoop-style.
Still need to accelerate all the hydrogen from it’s then-velocity up to cruising velocity, but not in a lump.